What he said. The instructors know that many of you are new new hires, and they know what to look for. They want you to pass as much as you yourselves want to pass. They will work with you to help you out if you fixate or mis-scan some other way. Try to relax and enjoy the process.
The first Sim is usually a major goat rope, so don't let it get to you. Typically, every sim thereafter is an improvement.